This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2001-093667, filed Mar. 28, 2001, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a manufacturing method of a semiconductor device for exposing a circuit pattern of the semiconductor device in a character projection system, a charged particle beam exposure apparatus of the character projection system, an aperture mask data preparing method for use in exposing respective layers of the circuit pattern using the exposure apparatus and an exposure data preparing method.
2. Description of the Related Art
When a resist pattern of a semiconductor device is prepared by electron beam (EB) exposure, it is necessary to convert data for each layer of a device pattern for each step of preparing the device, and to prepare exposure data having a data form able to be inputted into an exposure apparatus.
A shape of the pattern formed on a resist differs with respective layers. Therefore, when exposure data for each layer is prepared, and the pattern of the corresponding layer is exposed, the corresponding exposure data is inputted to an exposure control apparatus or the exposure apparatus.
The following problems occur in the conventional method.
Since data conversion is repeated for each layer of the pattern to be exposed, the data conversion has to be performed for all the layers. For example, since even one layer requires a conversion time of several hours, the time required for the data conversion of all the layers becomes very long, and the conversion is frequently unfinished in one day.
It is necessary to prepare the exposure data for the number of layers of the pattern to be exposed, and storage apparatuses such as a very large hard disk drive are required in a computer for the data conversion. For example, the exposure data requires a disk space of about 100 megabytes (MB) or more even in one layer. When ten layers in total are exposed, a capacity well over a gigabyte is required.
(1) According to one aspect of the present invention, there is provided a manufacturing method of a semiconductor device in which a circuit pattern of each layer of the semiconductor device designed by using standard cells is exposed by a character projection system, the method comprising: allocating one aperture block to each layer defined in standard cells, and setting an aperture mask in which only character apertures corresponding to a character shape extracted from the associated layer are arranged in an exposure apparatus in each aperture block; moving the aperture mask in such a manner that the associated aperture block can be irradiated with charged particle beam during exposure of an optional layer; and shaping the charged particle beam by the character apertures arranged in one aperture block, and exposing a circuit pattern of one layer.
(2) According to another aspect of the present invention, there is provided a charged particle beam exposure apparatus comprising: an aperture mask in which character apertures having an aperture shape corresponding to a character shape extracted from each layer defined in a standard cell for use in a semiconductor device designed are arranged in order to irradiate a sample with charged particle beam shaped by the character apertures, wherein aperture blocks as regions able to be irradiated with the charged particle beam by deflection are associated with respective layers defined in the standard cell and set in the aperture mask, and only the character apertures corresponding to the character shape extracted from the associated layer are arranged in each aperture block.
(3) According to another aspect of the present invention, there is provided a preparing method of aperture mask data comprising: extracting a pattern of each layer defined in a standard cell for use in a semiconductor device designed by using standard cells as a character; associating an aperture block as a region able to be irradiated with charged particle beam by deflection with each layer defined in the standard cell and setting the aperture block in the aperture mask; and arranging character apertures having an aperture shape corresponding to a character shape extracted from the associated layer in each aperture block.
(4) According to another aspect of the present invention, there is provided an exposure data preparing method comprising: extracting a pattern of each layer defined in a standard cell for use in a semiconductor device designed by using standard cells as a character; designing a pattern layout of an aperture mask in which character apertures corresponding to the extracted characters are arranged in a plurality of aperture blocks able to be irradiated with charged particle beam by deflection; and generating one piece of exposure data in which position information of the character apertures in the aperture blocks, and an irradiation position of a sample with the charged particle beam shaped by the character apertures are recorded and which is common to the plurality of layers defined in the standard cell based on the layout of the designed aperture mask.
(5) According to another aspect of the present invention, there is provided a manufacturing method of a semiconductor apparatus using a charged particle beam exposure apparatus in which a character is extracted from a pattern of each layer of a circuit pattern of a semiconductor device, which comprises an aperture mask with character apertures having an aperture shape corresponding to an extracted character shape arranged therein, and in which a sample is irradiated with charged particle beam shaped by the character apertures, the method comprising: associating the aperture block as a region which can be irradiated with the charged particle beam by deflection with each layer defined in a standard cell and setting the aperture block in the aperture mask; arranging only the character apertures corresponding to the character shape extracted from the associated layer in the aperture block; moving the aperture mask in such a manner that the associated aperture block can be irradiated with the charged particle beam during exposure of the optional layer; and shaping the charged particle beam by the character apertures arranged in the aperture block during the exposure.